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Sen. Chris Murphy is a Connecticut Democrat known for his gun control advocacy

He tweeted Monday "None of this ends unless we do something to stop it."

(CNN)Chris Murphy is unapologetically playing politics in the wake of the largest mass shooting in modern American history Sunday night in Las Vegas.

"It is positively infuriating that my colleagues in Congress are so afraid of the gun industry that they pretend there aren't public policy responses to this epidemic," the Connecticut Democratic senator said in a statement released Monday. "There are, and the thoughts and prayers of politicians are cruelly hollow if they are paired with continued legislative indifference. It's time for Congress to get off its ass and do something."

Murphy went even further via Twitter just after noon eastern. "To my colleagues: your cowardice to act cannot be whitewashed by thoughts and prayers," he tweeted. "None of this ends unless we do something to stop it."

Although Murphy, who represented Newtown in Congress at the time of the 2012 mass shooting at Sandy Hook elementary school, was the most forceful in his denunciation of the politics around gun control, he was far from the only one.

"Our grief isn't enough," tweeted Hillary Clinton. "We can and must put politics aside, stand up to the NRA, and work together to try to stop this from happening again."

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"How many more parents need to bury their children before Congress acknowledges the need to take action to reduce gun violence? #StopTheHate," tweeted Oregon Sen. Jeff Merkley (D).

That sort of willingness to talk politics in the immediate aftermath of these mass casualty shooting events is a huge change since Newtown.

Prior to the murders of 20 children and six adult staff members at the Sandy Hook Elementary School in 2012, any politician -- or prominent person -- who sought to make a political point about guns, gun violence or gun control in the immediate aftermath of these tragedies was usually shouted down or shamed. "How can you play politics at a time like this?" was the relentless refrain.

That remains a common sentiment. "Gun control is a legitimate issue, but for the Dems already raising it after Las Vegas massacre, could we just have a day before plunging in," tweeted Fox News' Howard Kurtz on Monday.

In the five years between Sandy Hook and Las Vegas, the question -- particularly among supporters of gun control -- has now become: How can you NOT play politics at a time like this? As in: The only way future Sandy Hooks or Las Vegases stop is if these tragedies are politicized in order to force action from our political system.

"You cannot accept the premise that there is any waiting period after a tragedy to start engaging in political action," Murphy told the Washington Post in 2016. "I think you need to be unapologetic about that. I am talking about legislative action within an hour of a shooting. These shootings won't stop unless we move seamlessly from tragedy to action."

Murphy sought to do just that in the wake of the 2016 Pulse nightclub shooting that left 49 people dead -- the largest mass casualty shooting event in modern American history prior to Sunday night. He staged a nearly 15-hour filibuster to protest the lack of any serious debate on the Senate floor over what, if any, gun control measures should be considered following the tragedy.

Republicans and even some Democrats, privately, view Murphy's outspoken activism through the lens of his personal ambitions. He is someone regularly mentioned as a potential candidate for the Democratic presidential nomination in 2020. And, politicians never, ever forget entirely about the political impacts of their words and actions -- especially in moments such as these.

Regardless of the mix of reasons -- personal conviction, politics etc. -- for Murphy (and other Democrats) to so quickly and forcefully bring politics to the fore after these increasingly common mass shootings, the fact is that it represents a drastic change in approach from even a decade ago.